Machine for automatically cutting slate into sheets



Deg. 10, 1929. A. PARNET 1,739,414

MACHINE FOR AUTOMATICALLY CUTTING SLATE INTO SHEETS Filed June 10, 1926 2 Sheets-Shes? 1 Dec. '10, 1929. A. PARNET 1,739,414

MACHINE FOR AUTOMATICALLY CUTTING SLATE INTO SHEETS Filed June 10, 1926 2 Sheets-Sheet 2 Fig.3

ii I 19 f a? 3a 35 2622 fb iy @Ui w 4 Patented Dec. 10, 1929 pt-ace.

ARSENE PARN'ET, or PARIS, FRANCE MACHINE FOR AUTOMATICALLY CUTTING SLATE INTO SHEETS Application filed J'une 10, 1926, Serial No. 115,103, and in France June 10, 1925.

The invention relates to splitting slate sheets and the like by means of a knife of relatively slight thickness of blade which is moved in the splitting'direction of the object retained between resilient jaws.

In accordance with the invention a relatively narrow blade is suitably driven by hammer blows into the sheet-formed object intermittently moved byits periphery to the knife, so that the splitting is effected zonew-ise from the entire periphery toward the center until complete separation. Economical splitting with relatively slight cost of power is thus possible in this manner.

Operation is carried on particularly advantageously in that the knife blade, after each driving in movement undergoes a number of short reciprocatory movements in the direction of the plane of'the blade, in order to facilitate and accelerate thesplitting operation by repeatedly producing and removing the splitting tension.

In the drawing there are illustrated solely by way of example two forms of construction of the invention. 1:

Figure 1 is a view in elevation of the machine, the drive means being removed.

Figure 2 is a view in plan of the complete machine. 1 I

Figure3 is a section ontheline III-III of Figure 2.

Figure 1 is a section on the line IV-IV of Figure 2.

Fig. 4 is a section taken along the line Iv -JV of Fig. 4.

As shown in Figures 1 and 2 the workpiece 1 is held at'the end of a shaft 2 between a plate 3 keyed to the shaft 2 and a second plate 4 adjusted to move in the direction of the shaft, and a spring 5 presses against the plate 3. Anoperating lever 6, which passes through an. extension 7 of the plate 4, and which can oscillate about its lower end 8, permits the plate 4 to be separated from the plate 3 in order to place the workpiece in position. The purpose of these plates is to hold the workpiece and to present it in front of the splitting chisel in such a manner thattheplane ofcleavage of the workpiece is parallel to the plane of the chisel.

Parallel to the shaft 2 and at a certain distance from this latter, a second shaft 9 is mounted on columns secured to the framework of the machine. This shaft 9 carries near one of its ends a cam 10 the object of whichis to raise the hammer 11 adapted to facilitate the sinking of the chisel into the workpiece. The chisel 12 ismounted at one end of a slide 13 sliding within the guide 14. The other end of the slide 13 is prolonged by a rod 15 on the end of which the hammer 11 strikes each time that the shaft 9 makes a complete revolution. A second cam 16 secured to the shaft 9 acts periodically through the mediumof a pusher 17 upon the upper end of a lever 18 oscillating about anaxis 19. The cam 16 as shown on Figure 3 has an irregular part between the lobes a and a which is intended to permit the disengagement of the chisel from the slatelwhen the latter has been completely split. Itis noted that in the illustrated embodiment the cam has seven lobes. This is intended to work a slate of determined fissility which necessitates the use of seven blows to split the slate completely. In the case of a slate of irregular fissility the cam carries only asingle lobe and the shaft is rotated until the slate is completely split. The lever 18 may be adjusted relatively to the cam 16 by means of the screw 29. The lower end of the lever 18 engages a sleeve 21 which" can slide at right angles to the shaft 9. In the interior of this sleeve 21 may freely slide a rod 22 terminating by a pusher 23guided in its movement by a guide 24. A spring 25 bears at one end upon the sleeve 21 and at the other endagainst the pusher 23holding the end of the latter against a beam 26 oscillating about the point 27. One end of the beam 26 engages through a slot 28 with a barrel 28 which can turn in the interior of the slide 13. A slot 26' in said guide gives access to the end of said beam, for lubrication and dismantling purposes of the chisel by pushing against the roller 31 secured to the beam.

A rod 32 is connected to the rear end of the beam 26 by a double actuation havingthe pivots c and (5 arranged perpendicularly so as to permit universal movement between the with a ratchet wheel 40, which is'keye'd on.

shaft 2. Shaft 79 is driven or entrained by means of crank 41 throughreducing gears 42.

The operation of the apparatus is as follows:

The object (work piece) 1 having been positioned between its two plates, by simply removing, through operating lever 6, the movable plate 4 from the fixed plate 3, crank 41 is rotated. When the flange of cam 10 reaches lever 43, integral with hammer 11, this latter is removed from its vertical position of rest; it is raised for an angular movement until "the moment in which the cam 10 leaves lever 43. The hammer then strikes against the end of extension 15 of the chisel support slide 13, which has the effect of causing the chisel to penetrate into the object, that is, to work the material.

Shaft 9 continuing to rotate, cam 16 exerts successive thrusts on pusher 23, through the pusher 17 and lever 18. These thrusts cause the chisel 12 to penetrate into the interior of the object 1. On the other hand, cam 30, on slidin on roller 31 attached to the end of beam 26 causes the successive withdrawals of the chisel in the object. The assembled apparatushas the effect of exerting on the chisel an. appreciable thrust which is regulated by regulating lever 18.

The reciprocating movement (to and fro) of bean 26, a movement which is controlled by cam 30, is transmitted by rod 32 to lever 34 and to its lug 35. The play of this lug at the interior of slit 36 is regulated by means of screws 38, on whose ends said lug may contact alternately. This play permits the preliminary withdrawal of the chisel along its axis over a distance which may vary from zero to a maximum quantity. When this play is taken up the lug 35 acts on the pawl lever 37, the result of which is to advance one tooth of wheel 40. Plate 3 and the object 1 rotate, at the same time as this wheel, for an angle the amplitude of which is regulated by the length of lever 34, afterthe chisel has withdrawn along its axis for the necessary length.

At the moment in which cam 10 raises hammer 11 chisel 12 is automatically withdrawn from the object and is placed in position for new penetration: I

It is to be understood that the invention is not limited to the exact constructions described and shown on the drawing. and that the machine may undergo modifications of detail as to construction without departing from the inventional scope.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is 1. A machine for splitting 'slate'comprising a rotating workpiece holder and a reciprocati-ng chisel, the latter moving in a plane perpendicular to the axis of rotation of said workpiece holder, said holder including face plates, one ofthe latter being spring-pressed toward the other, and means for reciprocating said 'chisel. V V

2. A machine for splitting slate comprising a rotary workpiece holder and a reciprocating chisel, said workpiece holder being adapted to hold. the slate with its plane of cleavage parallel to the direction of movement of said chisel, means for reciprocating said chisel, a hammer actuated by said reciprocating means for periodically imparting an inserting blow to said chisel, and means for withdrawing said chisel after the imparting of said series of blows.

p 3. A machine for splitting slate as claimed in claim 2, including a resilient cushion between elements of said chisel reciprocating means to compensate for variations in the length of the chisel stroke due to differences in its extent of penetration.

4. A machine for splitting slate as claimed in claim 2, in which the chisel reciprocating means also operates the rotary workpiece holder.

5. A machine for splitting slate comprising a rotary workpiece holder and a reciprocat-ing chisel, said workpiece holder being adapted to hold the slate with its plane of cleavage parallel to the direction of movement of said chisel, means for reciprocating said chisel, and a hammer for periodically imparting an impact blow to said chisel.

6. A machine for splitting slate as claimed in claim 5, in which the chisel reciprocating means also operates the rotary workpiece holder, said means including a resilient cushion between elements of said chisel reciproeating means to compensate for variations in the length of the chisel stroke due to differences in its extent of penetration.

7. A machine for splitting slate as claimed in claim 5, including connecting means between said chisel reciprocating means and the workpiece holder by which said workpiece holder is operated, said connecting means having a lost motion whereby the chisel may make reciprocatory movements of less than a certain amplitude without the workpiece holder being actuated.

8. A machine for splitting slate as claimed in claim 5, including connecting means between said chisel reciprocating means and said workpiece holder by which said holder is operated, said connecting means havingia lost motion whereby the chisel may make reciprocatory movements of less than a certain amplitude without the workpiece holder being actuated, and means for regulating the extent of said lost motion, thereby determining at what depth of cut the advance movement of the workpiece holder shall begin.

9. A machine for splitting slate as claimed in claim 5, including means for varying the length of stroke of said chisel reciprocating means.

10. A machine for splitting slate as claimed in claim 5, including positive means for withdrawing the chisel on its return or idle stroke.

11. A machine for splitting slate as claimed in claim 5, including cams for alternately advancing and retracting the chisel.

12. A machine for splitting slate as claimed in claim 5, in which the chisel reciprocating means also operates the rotary workpiece holder, said chisel reciprocating means including an intermediately pivoted lever, operatively connected at one end to said chisel, and at the other to said workpiece holder, yielding means acting at one side ot the fulcrum of said lever for impelling said chisel forward, a cam for operating said yielding means, and another cam acting upon the opposite side of the fulcrum of said lever for positively returning said chisel.

13. A machine for splitting slate as claimed in claim 5, in which the chisel reciprocating means also operates the rotary workpiece holder, said chisel reciprocating means including an intermediately pivoted lever operatively connected at one end to said chisel and at the other to said workpiece holder, yielding means acting at one side of the fillcrum of said lever for impelling said chisel forward, a cam for operating said yielding means, and another cam acting upon the opposite side of the fulcrum of said lever for positively returning said chisel, the connection of said chisel reciprocating means to said rotary workpiece holder including a pawl and ratchet drive arranged to advance said rotary workpiece holder step by step only on the penetrating strokes of said chisel.

14. A machine for splitting slate comprising a rotary workpiece holder and a reciprocatory chisel, and means for advancing the rotary workpiece holder by angular steps proportional tothe length of stroke of said chisel, the length of the stroke being adjustable according to the ease of penetration of the material acted upon.

ARSENE PARNET. 

